Submitted to: Obesity
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/20/2006
Publication Date: 10/1/2006
Citation: Garcia, J.M., Iyer, D., Poston, W.S.C., Marcelli, M., Reeves, R., Foreyt, J., Balasubramanyam, A. 2006. Rise of plasma ghrelin with weight loss is not sustained during weight maintenance. Obesity. 14(10):1716-1723. Interpretive Summary: The purpose of this study was to determine the relationship of plasma ghrelin, postulated to promote weight gain after weight loss, to active weight loss and weight maintenance in obese subjects. The participants were either assigned to intervention or no intervention. Intervention included diet, exercise, and orlistat, and lasted for a 12-month period. The results were consistent with previous results in that ghrelin rises in response to weight loss, perhaps as a counterregulatory mechanism. However, this study suggests that ghrelin concentrations return to baseline with sustained weight maintenance, suggesting that its effects are unlikely to regulate long-term energy balance.
Technical Abstract: Ghrelin is postulated to be an orexigenic signal that promotes weight regain after weight loss (WL). However, it is not known whether this putative effect of ghrelin is sustained after weight stabilization. The objective of this study was to investigate the relationship of plasma ghrelin concentrations to active WL and weight maintenance in obese subjects. This study was a randomized clinical trial, with a 12-month follow-up period. Obese Mexican-American women matched for age and BMI were randomized to a 12-month WL program (n = 25) or no intervention (controls, n = 23). Interventions included diet, exercise, and orlistat. Body weight and fasting ghrelin, leptin, insulin, and glucose concentrations were measured at baseline and 6 and 12 months. The WL group lost 8.5% of body weight after 6 months and maintained the new weight for the next 6 months. Ghrelin concentrations increased significantly at 6 months but returned to baseline at 12 months. Baseline ghrelin concentrations were directly related to the degree of WL achieved after 12 months. Controls experienced no change in BMI or ghrelin levels. There were no associations between plasma ghrelin and leptin or insulin concentrations. Consistent with previous results, ghrelin rises in response to WL, perhaps as a counterregulatory mechanism. However, the present results indicate that ghrelin concentrations return to baseline with sustained weight maintenance, suggesting that its effects are unlikely to regulate long-term energy balance. Baseline ghrelin concentrations are related to the degree of WL that can be achieved by active weight reduction.